Omenukwa, P. C. (2014). An ecclesiological exploration of the four marks of the church: An ecumenical option for the church in Nigeria : a study in the ecclesiology of Francis Alfred Sullivan. Peter Lang AG.

Omenukwa, Philip Chika. An Ecclesiological Exploration of the Four Marks of the Church: An Ecumenical Option for the Church in Nigeria : A Study in the Ecclesiology of Francis Alfred Sullivan. Frankfurt am Main, [Germany]: Peter Lang AG, 2014.

Omenukwa, Philip Chika. An Ecclesiological Exploration of the Four Marks of the Church: An Ecumenical Option for the Church in Nigeria : A Study in the Ecclesiology of Francis Alfred Sullivan. Peter Lang AG, 2014.